A n d r e w j



A. J. COCHRAN.

Tenoning Chisel.

Patented April 28, 1 868.

N. PEIERS. Phulo-ljflwgripbor, Walhinglan, n. c

To ALL WHOMVIT MAY CONCERN A NDR-E-W "CO-G'HRAN, or II-NIDIA NAP-OLITS. INDIANA.-

Lem Patent'lVo. 77,357, dated April 28,1868.

IMPROVEMENT IN remains-omens.

Etta 5x11251112 rennet tn in flgttt itettsts 3mm: ltltll making gaunt its same.

Be it known that L ANnRnw J. COCHRAN, of' Indianapolis, in the county of Marion, and State of Indiana, have invented anew and useful. Tenoning-Chisel; and 1.6.0 hereby declare that the .following is a full, clear," and exoefidescriptio'n of the same, reference bein had to the accompanying" drawing, and to the letters of I a reference marked thereon, making part of this specification.v

My invention relates to chisels' for cutting tcnons, and which are adapted to-use'in ordinary mortising;

machines, the novelty consisting in the arrangement of' two ndjustable bits, each having their edges formed in right angular'l'incs suitable to cutting the shoulder and paring the tenon: at the same time;

Figure 1 is a side view, and I 'I Figure 2 an edge view of the chisel.

Figure '3 is a view of the sto ckA. I

Similar letter-sot reference indicate corresponding parts in the several figures.

The'following description will enable skilled artisans to makeand use my invention. I

The'chisel is composed ofthe stock A and bits BB. The cutting-end or edge ofthe bit'is formed ata right angle, as shown, the part'that pares the tenon being made of considerable width, in order to make a clean,

smooth cut. The stock-A is adapted to fit :in the mandrel of ordinary mortising-machinos, and the chisel is used in a similar man'nerjto mortising-chisels.

In order ;to sustain the thrust in driving down the chisel, the stock is made with V-shape'il shoulders that.

restin eorresponding notches in the upper ends of thehit s, as shown, and the lower end of the stock is intnished with a short horizontal bar, (){formi'ng a part of the stock, and which projects from the sides far enough 'to-pass through the bits and help sustain them against the thrust, as well as preventing lateral movement.

Theupper ends of thebits are groovedon thc inside, clown tothe hole through which the bar 0 passes to receive the edges of the stock, and is thus arranged in order to give greater strength to the stock 'bythe extension of its cllges, an(l at the same time allow the-hits to be set as near to each otheras will be'practically required. h

The stock and upper-lends of the hits are draw-mortised, so that the key D will draw the bits-firmly against the .shoulil ersof the'stock. The bits may beset the proper distanee apart by uieans'of the set screw'sE E, the

opposite ends of which are'cutlwith right and left screws, as will he readily un'dcrstood from the-drawing.

Having thus fully described m'y inyention, what I claim as'new, anddesire'to'secure by Letters Patent, is- Theeombination o'f the-bits, B .13 with the-stock A C,,ke'y D, andright and left screws E, when constructed and arrangeilto operate substantially as described. I v I i ANDREW J. eoonnsn.

Witnesses:

SPENCER HIATT, 

